In an existing radio communications system, in order to guarantee transmission quality of high speed downlink data, when a user equipment (UE) is configured with a single transmission channel, or is configured with a single transmission channel, and meanwhile, the single transmission channel is configured with multiple-input multiple-output (MIMO), namely, single-transmission-channel+MIMO operation, or is configured with multiple transmission channels, or is configured with multiple-transmission-channel+MIMO operation, memory allocated to each hybrid automatic repeat request (HARQ) process does not exceed 43200 bits.
When a UE is configured with a 4*4 MIMO operation (it should be noted that the 4*4 MIMO operation is a kind of operation in an N*M MIMO operating system, where N represents the number of transmitting antennas, and M represents the number of receiving antennas), if the number of HARQ processes configured for each transmission channel in the 4*4 MIMO operation is the same as the number of HARQ processes configured for each transmission channel in the MIMO operation (12, 14 or 16 processes), as the data volume transmitted by each HARQ process in the 4*4 MIMO operation changes to two times of the data volume transmitted by each transmission channel in the MIMO operation, in the 4*4 MIMO operation, memory allocated to each HARQ process does not exceed 86400 bits. If the number of HARQ processes configured for each transmission channel in the 4*4 MIMO operation (24, 28 or 32 processes) is double the number of HARQ processes configured for each transmission channel in the MIMO operation, in this case, as the data volume transmitted by each HARQ process in the 4*4 MIMO operation is the same as the data volume transmitted by each transmission channel in the MIMO operation, the number of soft channel bits obtained by each HARQ process does not exceed a maximum memory threshold value, namely, 43200 bits.
In existing HARQ process memory allocation, the UE obtains an HS-DSCH physical layer category corresponding to a high speed downlink packet access (HSDPA) capability thereof based on an existing high speed downlink shared channel (HS-DSCH) physical layer category standard, and reports the corresponding HS-DSCH physical layer category to a network device. For example, when the UE reports an HS-DSCH physical layer category corresponding to a capability of supporting a six-transmission-channel operation and the network device configures a five-transmission-channel operation for the UE, as the existing HS-DSCH physical layer category standard does not specify an HS-DSCH physical layer category that separately represents a five-transmission-channel operation, the UE uses, based on the configured five-transmission-channel operation, an HS-DSCH physical layer category corresponding to the six-transmission-channel operation in the HS-DSCH physical layer category standard, queries the HS-DSCH physical layer category standard according to the HS-DSCH physical layer category corresponding to the six-transmission-channel operation, to obtain the total number of soft channel bits 3110400 of a soft memory buffer of a media access control (Media Access Control-hs/ehs, MAC-hs/ehs) entity corresponding to the six-transmission-channel operation, allocates the total 3110400 soft channel bits among the actually configured five transmission channels (HS-DSCH transmission channels), determine that the number of soft channel bits obtained by each transmission channel is 622080, and further allocates the soft channel bits obtained by each transmission channel among all HARQ processes. Assuming that the number of pre-configured HARQ processes is 12, the number of soft channel bits 622080 obtained by each transmission channel is divided by the number of HARQ processes 12, to acquire that the number of soft channel bits obtained by each process is 51840, which exceeds the maximum memory threshold value for each HARQ process, namely, 43000 bits. The system will generate an HARQ process memory allocation error, and normal data transmission is affected.
Therefore, if the HARQ process memory allocation is carried out based on the existing HS-DSCH physical layer category standard, because the existing HS-DSCH physical layer category standard does not specify HS-DSCH physical layer categories that separately represent five-transmission-channel and seven-transmission-channel operations or HS-DSCH physical layer categories corresponding to 4*2 MIMO and 4*4 MIMO operations, when the network device configures the UE on the five-transmission-channel operation, seven-transmission-channel operation, 4*2 MIMO operation, and 4*4 MIMO operation, an error occurs in HARQ process memory allocation, which reduces data transmission efficiency.